Use UINT64_MAX instead of implicitly-type-converted -1.

llvm-svn: 314126
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 0baa212..e72a20d 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -428,7 +428,7 @@
 
 void LinkerScript::fabricateDefaultCommands() {
   // Define start address
-  uint64_t StartAddr = -1;
+  uint64_t StartAddr = UINT64_MAX;
 
   // The Sections with -T<section> have been sorted in order of ascending
   // address. We must lower StartAddr if the lowest -T<section address> as